Extension arm



FIG. 1 is a top perspective view of an extension arm showing my new design;

FIG. 2 is a right side elevation view thereof, the left side elevation view being a mirror image thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a partially exploded bottom perspective view of an extension arm;

FIG. 6 is an enlarged view of the encircled area of FIG. 5;

FIG. 7 is an enlarged rear elevation view of an extension the extension arm shown in FIG. 1;

FIG. 8 is a front elevation view thereof;

FIG. 9 is a side view of the extension arm in a representative environment, the dashed lines are directed to environment and form no part of the claimed design; and,

FIG. 10 is an exploded top perspective view of the extension arm.

The wire frame lines shown throughout the views indicate surface contour. 

CLAIM The ornamental design for an extension arm, as shown and described. 